Vasovagal Syncope | Assessment of Midodrine in the Prevention of Vasovagal Syncope: The Prevention of Syncope Trial IV

Vasovagal Syncope research study

What is the primary objective of this study?

About 20% of adults faint recurrently. These patients are often highly symptomatic, have problems with employment and driving and have reduced quality of life. There are no therapies that have withstood the test of adequately designed and conducted randomized clinical trials. Midodrine is a prodrug whose metabolite is an alpha-1 adrenergic agonist that increases venous return to the heart and raises blood pressure. There is considerable lower level evidence that it might prevent vasovagal syncope. The investigators will test the hypothesis that Midodrine prevents recurrences of syncope in patients with moderate to severe vasovagal syncope.

Who is eligible to participate?

Inclusion Criteria: - Patients will be eligible if they have: - ≥2 syncopal spells in the year preceding enrolment, and - ≥ -2 points on the Syncope Symptom Score for Structurally Normal hearts, and - Age ≥ 18 years with informed consent. Exclusion Criteria: - Patients will be excluded if they have: - other causes of syncope, such as ventricular tachycardia, complete heart block, postural hypotension or hypersensitive carotid sinus syndrome, - an inability to give informed consent, - important valvular, coronary, myocardial or conduction abnormality or significant arrhythmia, - hypertrophic cardiomyopathy, - a permanent pacemaker, - a seizure disorder, - urinary retention, - hypertension defined as >140/90 mm Hg, - hepatic disease, - glaucoma or - a 5-minute stand test resulting in diagnoses of Postural Orthostatic Tachycardia Syndrome or Orthostatic Hypotension.

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Vasovagal Syncope

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Drug:midodrine hydrochlorideTarget dose is midodrine hydrochloride or placebo pills 10 mg three times a day for 12 months. The starting dose is 5mg q4h x3, and if tolerated a forced titration up to 10mg/dose. If there is an intolerance, then the dose can be reduced to 2.5mg/dose.

Drug:matching placeboThe target dose in this study is 10mg q4h x3 for 12 months. The starting dose is 5mg q4h x3, and if tolerated a forced titration up to 10mg/dose. If there is an intolerance, then the dose can be reduced to 2.5mg/dose.

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

midodrine hydrochloride pills

oral placebo or sugar pill

Study Status

Active, not recruiting

Start Date: November 2011

Completed Date: July 31, 2019

Phase: Phase 4

Type: Interventional


Primary Outcome: The primary outcome measure will be the proportion of patients having at least one syncope recurrence.

Secondary Outcome: A secondary outcome will be the time between the first and second syncope recurrences.

Study sponsors, principal investigator, and references

Principal Investigator:

Lead Sponsor: Dr. Bob Sheldon

Collaborator: Vanderbilt University

More information:

Discuss Syncope